280 DEPARTMENTAL EEPORTS. 



The investigations planned for the j-ear have been completed and 

 for the most part the reports of the results have been received. These 

 reports will be i^repared for publication as rapidly as possible. 



THE WORK AT DIFFERENT PLACES. 



During the past j^ear the work of the Washington office in connection 

 with the nutrition investigations has included a general supervision of 

 the plans and expenditures, editorial work in the preparation of bulle- 

 tins and in perfecting the details of reports of investigations, the col- 

 lection and compilation of the results of nutrition investigations not 

 generally available, the collection of bibliographical data and the 

 abstracting of the current literature on nutrition — partly for publica- 

 tion in the Experiment Station Record, the conducting of a large 

 correspondence growing out of nutrition investigations, and the dis- 

 tribution of publications on this subject. 



The work in Middletown, Conn., at the office of Prof. AV. O. Atwater, 

 special agent in charge of nutrition investigations, has included the 

 planning and direct supervision of these investigations in different 

 parts of the country, the conducting of special investigations with 

 the respiration and bomb calorimeter, the compilation of results of 

 nutrition investigations in this country and abroad, correspondence 

 relating to these investigations, and administrative work. 



The special investigations at Middletown were under the more 

 immediate charge of Dr. F. G. Benedict, and as heretofore were carried 

 out in cooperation with the Storrs Experiment Station and with Wes- 

 leyan University. They include routine and special analj^tical work 

 and metabolism experiments, which also eomj^rise digestion experi- 

 ments and an experimental study of methods of determining water 

 in food samples. Attention has also been given to the imj)rovement 

 of the respiration calorimeter and other apparatus and methods of 

 experimenting. 



The principal objects of the investigations with the respiration 

 calorimeter were the studj^ of the relative efficiency of fats and carbo- 

 hydrates as sources of energy for the performance of muscular work. 

 The observations included also the amount of heat liberated by the 

 body during the period of digestive inactivity as compared with that 

 in the period when digestion is taking place, the metabolism of nitro- 

 gen during fasting, and the variations of body temperature under 

 different conditions. 



Two series of experiments were carried on during the j^ear. The 

 first, of six days' duration, comprised a work experiment of three 

 days with a diet containing a large quantity of carbohydrates, and a 

 fasting experiment of two days, in which the subject remained as 

 quiet as jjossible Avithin the respiration chamber. On the day between 

 these two experiments the subject ate part of a day's rations and 

 remained quiet. The second series of experiments covered a period of 

 ten days. The purj)ose was to comj^are the values of fats and carbo- 

 h3"drates as sources of energy for the performance of muscular work. 

 On the last day of this series the subject performed an unusual amount 

 of work, sleeping only two hours out of the twenty-four. It is believed 

 that the data furnished by these two series of experiments are 

 especially interesting. 



Several of the so-called " check" experiments for testing the accu- 

 racy of the apparatus by burning alcohol within the chamber were 

 made during the j^ear. These are believed to be in several respects 

 the most valuable of such check expci-iments thus far carried on. 



